IT has to go above the door jamb so it will overflow before it gets above the hot mop. But a hot mop pan is the least desirable thing to install. It will fail long before the tile does. We replace tar paper pans quite frequently.

: i'm replacing my walk in shower, and there is tar and tar paper that is sealing the shower from the sub floor. is there information on the spects on how high up the wall the hot mop should go?